Overview
A hybrid bioprinter has been developed to produce artificial capillary networks with dimensions smaller than 10 micrometers. This advancement is directed at addressing a significant bottleneck in tissue engineering, specifically the creation of perfusable vascular systems necessary for the viability and function of larger engineered tissues and organs. The inability to adequately vascularize engineered tissues currently limits their size and clinical applicability.
Research Context
The field of tissue engineering aims to create functional tissues and organs for transplantation, which could potentially alleviate the significant demand for organ donors. In the United States, over 100,000 individuals are awaiting organ transplants, with a new candidate added approximately every 10 minutes. While successful transplantation provides a life-saving option, recipients face lifelong immunosuppressive medication regimens. These medications increase the risk of broader infections and necessitate strict lifestyle adherence, alongside the continuous possibility of organ rejection. A primary obstacle to engineering larger, clinically relevant tissues is the absence of a pervasive vascular network to supply nutrients and oxygen and remove waste products. Existing biofabrication methods have struggled to create capillary-scale structures that are critical for long-term tissue viability.
Approach
The research involved the development and application of a hybrid bioprinting system. This system integrated microextrusion-based bioprinting with laser-assisted bioprinting. The microextrusion component was utilized for the deposition of hydrogels, providing the structural scaffold, while the laser-assisted component was employed to create the fine-scale capillary networks. The design of this hybrid approach aimed to leverage the strengths of both techniques: the ability of microextrusion to handle bulk tissue structures and the precision of laser-assisted printing for fabricating intricate microvascular architectures. The critical objective was to achieve printed capillaries with diameters less than 10 micrometers, a size range conducive to efficient nutrient and oxygen exchange, mirroring natural biological systems.
Findings
- The hybrid bioprinter successfully fabricated perfusable artificial capillary networks.
- The created capillary networks demonstrated widths narrower than 10 micrometers.
- This capability directly addresses a key challenge in tissue engineering: the construction of perfusable vascular structures.
- The integration of microextrusion-based bioprinting and laser-assisted bioprinting proved effective for creating both macro-scale tissue constructs and micro-scale vascular networks.
Why This Matters
The development of this hybrid bioprinting technology represents a step towards overcoming the vascularization barrier in tissue engineering. By enabling the creation of capillary networks narrower than 10 micrometers, it facilitates the design of larger and more complex engineered tissues that can receive adequate nutrient and oxygen supply and waste removal. This foundational capability is crucial for the eventual clinical translation of engineered organs, which could reduce reliance on donor organs and the associated challenges of immunosuppression and organ rejection.